I rarely re-read; in fact that only books I've ever re-read were the Hitchhiker's Guide books, and Hyperion. I just find that I'd much rather have a new experience.
I also don't really have any books I'd consider "comfort books". My favourite books of all time are 1984, A Canticle for Leibowitz and Fahrenheit 451; nothing that I'd consider reading as a pick-me-up
Edit
Come to think of it, I really don't like re-watching movies either. I think a big part of the experience for me is novelty and surprise, without those I'm not that interested. I also find that a second reading/watching lessens the emotional impact, so I don't remember the book/movie as fondly.